Scientists at TalTech in Estonia are researching whether medicinal plants native to Estonia can be used in the fight against Lyme disease and the bacteria that cause it. With approximately one in three ticks in Estonia carrying the bacteria responsible for borreliosis and up to one in four ticks in the capital city of Tallinn being carriers, the prevalence of tick-borne diseases has increased significantly in the country over the past decade.
The recently published "Mail a Tick!" project by the National Institute for Health Development revealed that at least one pathogen was detected in 62.3% of all ticks examined, including those responsible for well-known tick-borne diseases like tick-borne encephalitis and borreliosis.
While vaccination is available for tick-borne encephalitis, there is currently no preventive treatment for Lyme disease. The disease, caused by the Borrelia burgdorferi sensu lato bacteria, enters the human bloodstream through tick bites. Initial symptoms include an enlarging reddish patch around the bite site, although this may not be present in up to one-third of cases. If left untreated, Lyme disease can have severe consequences, affecting the joints, nervous system, skin, and heart.
According to the National Institute of Health, approximately 28% of ticks in Estonia carry B. burgdorferi, and more than 2,500 people contract Lyme disease each year. A comparison of recent data with surveys conducted between 2006 and 2009 and 2012 and 2014 indicates that the prevalence of Lyme disease in ticks has doubled or tripled in some areas across Estonia.
It's important to note that tick-borne diseases are not limited to rural areas but can also be contracted in cities. A survey conducted by the National Institute for Health Development in 2018 found that an average of 35% of ticks collected from urban green areas carried at least one pathogen, with the prevalence of bacteria causing Lyme disease reaching 25% in certain locations.
The current treatment for Lyme disease involves antibiotics, which are generally effective in the acute stage. However, if the disease goes unnoticed and treatment is delayed, it can become chronic.
Persistent symptoms are often caused by more resistant forms of the B. burgdorferi bacteria, such as round body forms and biofilm, which are less susceptible to antibiotics than the original corkscrew-shaped spirochetes.
To combat these resistant forms of bacteria, innovative treatments are required. Numerous scientific studies have highlighted the potential efficacy of plant-derived compounds or phytochemicals against Lyme disease.
TalTech's instrumental analysis research group has been investigating Estonian plants for an extended period. Their recent focus has been identifying phytochemicals that effectively combat B. burgdorferi and discovering new lead compounds suitable for treating chronic Lyme disease.
While several Estonian plants are recognized as medicinal herbs with potential antibacterial properties, their alleged benefits often lack scientific confirmation. Researchers can identify specific plant compounds responsible for various therapeutic properties by conducting chemical studies on Estonian plants.
The instrumental analysis research group studies many plants found in Estonia, many known for their medicinal properties. Their research aims to provide an overview of various local plant extracts' chemical composition and beneficial properties. Initially, the researchers focus on characterizing the chemical makeup of the studied species, identifying the main groups of compounds present, and assessing the antioxidant properties of the plant extracts.
Antioxidant activity in an extract indicates its potential therapeutic use as an antibacterial agent and in treating diseases associated with oxidative stress, such as cancer. Researchers have much more work to do before any complete conclusions can be made.